The W.M. Keck Center for Cellular Imaging (KCCI), an internationally recognized center for advanced light microscopy imaging that is particularly known for protein-protein interaction imaging, is requesting a Leica TCS SP5X "Tunable White Light Laser Confocal/Spectral Imaging Microscopy" system. KCCI is a University wide imaging facility and the requested instrument will benefit the basic and clinical science investigators of this university, and particularly the 8 participating federally funded investigators. The instrument will be housed in the KCCI, located within walking distance of all the participating investigators. The central theme of the research to be performed on the requested Leica TCS SP5X is the study of protein-protein interactions in live cells and other cellular imaging including Photoactivated GFP (PA_GFP) to monitor the dynamic protein interactions in pituitary GHFT1 cells, IQGAPs and the Cell Biology of Alzheimer's Disease, characterization of new FRET pairs, glutamine FRET sensors, study of the mechanism of actin assembly at membranes, and monitoring dynamic behavior of multiple molecular components of the cell biological system during embryonic development. The requested instrument, the Leica SP5X system is unique and represents a quantum leap in confocal microscopy, providing users the ability to tune the excitation and emission wavelengths to match exactly the fluorophores in their experimental samples. The user no longer needs to adapt the experiment to the laser lines available on the confocal system;the tunable white light laser system adapts to the particular experiment. There is currently no other system available at the University of Virginia that has a tunable (470-670 nm) white light laser confocal/spectral imaging capability. This is essential for our core investigator group, and will also be critical for training other investigators interested in the study of protein associations in living cells and tissues. The KCCI is recognized for its annual hands-on-training course, held for the past seven years at the University of Virginia. To date, 304 scientists, from the United States as well as scientists from 23 countries have participated in the KCCI workshop. In summary, the requested instrument will provide the research community at the University of Virginia with a level of imaging capability that is not currently available, and this will enhance significantly ongoing and future research. PUBLIC HEALTH RELEVANCE: The non-invasive detection of biological events inside the living cell was made possible by the many different color fluorescent proteins, but this approach requires a highly adaptable microscope system. The requested Leica TCS SP5X tunable white light laser system is a unique system that permits the user to tune the excitation and emission wavelengths to match exactly the fluorophores in their experimental samples. If we have to understand disease processes and design therapeutic strategies, it is important to continue to develop these live-cell imaging technologies, and the combination of different color fluorescent proteins and the requested Leica SP5X represents a substantial advance in this area.